Three step deep reactive ion etch for high density trench etching

Lips, Bram; Puers, Robert

doi:10.1088/1742-6596/757/1/012005

Cited by 10 publications

(11 citation statements)

References 5 publications

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“…Alternative approaches for sidewall verticality improvement can include cyclic passivation of the sidewalls as known from silicon deep reactive ion etching (Bosch process). In silicon, sidewall angles of 89.7° have been demonstrated for similar etching depths of 130 µm 45 . Such quasi-ideal sidewall angles are obtained by adjusting the etching time to passivation time ratio 46 .…”

Section: Resultsmentioning

confidence: 88%

Precision micro-mechanical components in single crystal diamond by deep reactive ion etching

et al. 2018

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The outstanding material properties of single crystal diamond have been at the origin of the long-standing interest in its exploitation for engineering of high-performance micro-and nanosystems. In particular, the extreme mechanical hardness, the highest elastic modulus of any bulk material, low density, and the promise for low friction have spurred interest most notably for micro-mechanical and MEMS applications. While reactive ion etching of diamond has been reported previously, precision structuring of freestanding micro-mechanical components in single crystal diamond by deep reactive ion etching has hitherto remained elusive, related to limitations in the etch processes, such as the need of thick hard masks, micromasking effects, and limited etch rates. In this work, we report on an optimized reactive ion etching process of single crystal diamond overcoming several of these shortcomings at the same time, and present a robust and reliable method to produce fully released micro-mechanical components in single crystal diamond. Using an optimized Al/SiO 2 hard mask and a high-intensity oxygen plasma etch process, we obtain etch rates exceeding 30 µm/h and hard mask selectivity better than 1:50. We demonstrate fully freestanding micro-mechanical components for mechanical watches made of pure single crystal diamond. The components with a thickness of 150 µm are defined by lithography and deep reactive ion etching, and exhibit sidewall angles of 82°-93°with surface roughness better than 200 nm rms, demonstrating the potential of this powerful technique for precision microstructuring of single crystal diamond.

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Section: Resultsmentioning

confidence: 88%

Precision micro-mechanical components in single crystal diamond by deep reactive ion etching

et al. 2018

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“…A close-up image of a fabricated silicon spring, is shown in Figure 3a. The DRIE parameters used are based on [6]. A serpentine design was chosen in order to achieve small spring constants given the limited area between the silicon islands.…”

Section: Resultsmentioning

confidence: 99%

MEMS Enabled Bendable and Stretchable Silicon Circuits

Lips

Puers

2018

Eurosensors 2018

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We report the design and implementation of a unique, wafer sized stretchable and bendable monolithic silicon matrix structure. The achieved stretchability allows for simultaneous omnidirectional folding, required to conform the structure to complex curved 3D surfaces. Moreover, it also enables dynamic mechanical deformation of the structure to cope with a moving environment, like e.g., the wall of the heart muscle. Due to the nature of the fabrication process, normal silicon wafer processing can be performed prior to rendering it stretchable. This is first demonstrated by the fabrication of two metal layers on top of silicon, which act as the electrical interconnects of a final flexible and stretchable LED-matrix. Currently, the possibility to postprocess an existing commercial CMOS process is investigated. This would lead to a revolutionary potential of new applications, especially in the medical field, by enabling complex silicon monitoring systems to be linked to organs without hindering them.

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“…A three-step DRIE process, capable of achieving nearly vertical sidewalls with a scallop size of 30 nm, was used. 31 The process was based on the use of C 4 F 8 and SF 6 gases and was implemented on a PlasmaPro 100 Estrelas machine (Oxford Instruments). The pattern was etched 12–13 μm deep into the silicon.…”

Section: Methodsmentioning

confidence: 99%

“…The microstructures were fabricated on 4-inch silicon substrates (one side polished, (100), p-type) by standard lithographic patterning followed by a deep reactive-ion etching (DRIE) process to transfer the pattern into bulk silicon. A three-step DRIE process, capable of achieving nearly vertical sidewalls with a scallop size of 30 nm, was used . The process was based on the use of C 4 F 8 and SF 6 gases and was implemented on a PlasmaPro 100 Estrelas machine (Oxford Instruments).…”

Section: Methodsmentioning

confidence: 99%

Wafer-Scale Particle Assembly in Connected and Isolated Micromachined Pockets via PDMS Rubbing

et al. 2022

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The present contribution reports on a study aiming to find the most suitable rubbing method for filling arrays of separated and interconnected micromachined pockets with individual microspheres on rigid, uncoated silicon substrates without breaking the particles or damaging the substrate. The explored dry rubbing methods generally yielded unsatisfactory results, marked by very large percentages of empty pockets and misplaced particles. On the other hand, the combination of wet rubbing with a patterned rubbing tool provided excellent results (typically <1% of empty pockets and <5% of misplaced particles). The wet method also did not leave any damage marks on the silicon substrate or the particles. When the pockets were aligned in linear grooves, markedly the best results were obtained when the ridge pattern of the rubbing tool was moved under a 45° angle with respect to the direction of the grooves. The method was tested for both silica and polystyrene particles. The proposed assembly method can be used in the production of medical devices, antireflective coatings, and microfluidic devices with applications in chemical analysis and/or catalysis.

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Three step deep reactive ion etch for high density trench etching

Cited by 10 publications

References 5 publications

Precision micro-mechanical components in single crystal diamond by deep reactive ion etching

Precision micro-mechanical components in single crystal diamond by deep reactive ion etching

MEMS Enabled Bendable and Stretchable Silicon Circuits

Wafer-Scale Particle Assembly in Connected and Isolated Micromachined Pockets via PDMS Rubbing

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